Looping Problems
- I'd like to start by taking a look at a few head scratchers
- We will be revisiting these at the end of the talk, so I don't expect you to remember these
- I just want you to note that there are a few confusing things that we'll have resolutions for by the end of the talk
Looping Twice
>>> numbers = [1, 2, 3, 5, 7]
>>> squares = (n**2 for n in numbers)
>>> tuple(squares)
(1, 4, 9, 25, 49)
>>> sum(squares)
0
- `numbers` here is a list
- `squares` is a generator **(click)**
- this generator will give us the squares of each of those numbers
- If we pass this generator to the tuple constructor **(click)** it will make a tuple out of it **(click)**
- And if we pass the generator to the `sum` function **(click)** we'll get the sum of all the squared numbers
- **(click)** But the sum is `0`... but we expected a much bigger number
- So that's one oddity
Containment Checking
>>> numbers = [1, 2, 3, 5, 7]
>>> squares = (n**2 for n in numbers)
>>> 9 in squares
True
>>> 9 in squares
False
- If we ask whether `9` is in this generator **(click)**, Python will tell us this is `True` **(click)**
- 9 *is* in this generator
- If we ask the *same question* again **(click)**, Python will tell us this time, that it's `False` **(click)**
- We asked the same question twice and Python gave us two different answers.
- That's a little weird
Unpacking
>>> counts = {'apples': 2, 'oranges': 1}
>>> x, y = counts
>>> x
'apples'
- This dictionary has two key-value pairs
- If we try to unpack this dictionary into two variables **(click)**, you might think we'll get an error
- But we don't **(click)**... we can unpack dictionaries
- Okay that's a little odd, but let's just go with it
- You might expect at this point that `x` and `y` at this point are tuples of key-value pairs
- **(click)** But you'd be wrong.
- `x` and `y` are not tuples of key-value pairs... they're keys.
- That's a little weird also. We'll come back to that at the end of this talk.
Review Time
- We will explain what's going on in those examples by the end of this talk
- Now let's do a little bit of review
- I'd like to review loops, iterables, and sequences
- I want to review what these terms mean and how they work in Python
C-style for loop
let numbers = [1, 2, 3, 5, 7];
for (let i = 0; i < numbers.length; i += 1) {
print(numbers[i])
}
1
2
3
5
7
- This is not Python code.
- This is a traditional C-style `for` loop, written in JavaScript
- In this loop, we start with `i` set to `0`, we check whether `i` is less than the length of the `numbers` array, we loop, and we increment `i` by 1 each time we loop
- Once the condition is no longer true, we'll stop looping **(click)**
- So this `for` loop will print out each item in the array
- *(pause)* Python **does not** have this kind of `for` loop
- What we *do* have in Python is a for-*in* loop, which many programming languages call a **foreach loop**
Python for loop
numbers = [1, 2, 3, 5, 7]
for n in numbers:
print(n)
1
2
3
5
7
- This is a `for` loop in Python
- In this `for` we're looping over each item in our list and printing those items out **(click)**
- Python `for` loops don't have any index variables, index lookups, or index incrementing
- Python's `for` loops magically do *all the work* of looping over our `numbers` list for us
- So Python doesn't have traditional C-style `for` loops
- We do have something that we call a `for` loop but it works differently
Iterables are iter-able
for item in some_iterable:
print(item)
- *If* you can loop over something with a `for` loop in Python, *it is* an iterable
- And... if something *is* an iterable, you can loop over it with a `for` loop
- So if you're not sure what that word iterable means, it means anything that you iterate over
- Iterables can be looped over and anything that can be looped over is an iterable
Sequences
>>> numbers = [1, 2, 3, 5, 7]
>>> coordinates = (4, 5, 7)
>>> words = "hello there"
>>> numbers[0]
1
>>> coordinates[2]
7
>>> words[4]
'o'
- Sequences are a very common type of iterable
- **(click)** Lists are sequences, **(click)** tuples are sequences, **(click)** and strings are sequences
- **(click)** Sequences are iterables which can be indexed starting from ``0`` and ending at one less than the length of the sequence **(click)**
- **(click)** Lists, tuples, strings and *all other* sequences can be indexed this way
Other iterables
>>> my_set = {1, 2, 3}
>>> my_dict = {'k1': 'v1', 'k2': 'v2'}
>>> my_file = open('some_file.txt')
>>> squares = (n**2 for n in my_set)
>>> from itertools import count
>>> c = count()
- *Lots* of things in Python are iterables
- But *many* iterables in Python are **not** sequences
- **(click)** Sets are iterables
- **(click)** Dictionaries are iterables
- **(click)** Files are iterables
- **(click)** And generators are iterables
- **(click)** There are even infinitely long iterables, like `count` objects from the `itertools` module in the standard library
- *None* of these iterables are sequences
What we know
Python doesn't have traditional for
loops
Python does have a flavor of foreach
loops which we call for
loops
Anything that can be looped over in Python is an iterable
Sequences are a special type of iterable
Not all iterables are sequences
- So Python doesn't have traditional `for` loops
- But we do have something that we call a `for` loop
- Anything that can be looped over with a `for` loop is an iterable
- Sequences are just one type of iterable, but there are many other types of iterables
- So we're done with review at this point...
Iterators power for
loops
- Under the hood, Python's for loops rely on something called an **iterator**
- Iterators are the thing that powers `for` loops in Python
- You can get an iterator from any iterable in Python-
- And you can use an iterator to manually loop over an iterable
- Let's take a look at how that works
Iterables can give you iterators
>>> numbers = [1, 2, 3, 5, 7]
>>> coordinates = (4, 5, 7)
>>> words = "hello there"
>>> iter(numbers)
<list_iterator object at 0x7f2b9271c860>
>>> iter(coordinates)
<tuple_iterator object at 0x7f2b9271ce80>
>>> iter(words)
<str_iterator object at 0x7f2b9271c860>
- We have three iterables here: a list, a tuple, and a string
- We can ask each of these for an *iterator* using Python's built-in **`iter` function** **(click)**
- Passing an iterable to the `iter` function will always give us back an iterator **(click)**, no matter what type of iterable we're working with
- Lists, strings, and tuples are all iterables **(click)**
- And every iterable will provide us with an iterator when we pass it to the built-in `iter` function
Iterators can give the next item
>>> numbers = [1, 2, 3]
>>> iterator = iter(numbers)
>>> next(iterator)
1
>>> next(iterator)
2
>>> next(iterator)
3
>>> next(iterator)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
StopIteration
- Once we *have* an iterator, there is *only* one thing that we can do with it **(click)**: **get its next item**
- **(click)** We can use Python's built-in `next` function to get the *next* item **(click)** from *any* iterator
- And if you ask for the `next` item and there are **no more items** **(click)**, you'll get a `StopIteration` exception
- So you can get an iterator from every iterable
- And the only thing that you can do with iterators is ask them for their next item
- And if they don't have a next item you'll get an exception
- So you can think of iterators as kind of like one-directional tally counters, with a broken reset button
- They keep track of where they are as you ask them for their next item
- But they only go in one direction
- And they cannot be reset
- Iterators are one-directional tally-counts without a reset button
- Iterators are *also* kind of like a Hello Kitty PEZ dispenser that cannot be reloaded
- When you take a PEZ out, it's gone
- And once the dispenser is empty, it's useless
- Iterators are Hello Kitty PEZ dispensers that cannot be reloaded
A For Loop
def funky_for_loop(iterable, action_to_do):
for item in iterable:
action_to_do(item)
- Now that we know about iterators, we're going to try manually looping over an iterable once again
- We'll do that, by turning this `for` loop into a `while` loop
- We've already established that we can't use *indexes* to loop over an arbitrary iterables
- But we *can* get iterators from iterables
- And we can repeatedly get the next item from an iterator to loop over that iterable
- So that's what we're going to do
Looping without a for
loop
def funky_for_loop(iterable, action_to_do):
iterator = iter(iterable)
done_looping = False
while not done_looping :
try:
item = next(iterator)
except StopIteration:
done_looping = True
else:
action_to_do(item)
- In order to manually loop over an iterable **(click)** we need to get an iterator from it
- Then we can loop repeatedly **(click)**
- And get the *next* item from the iterator each time we loop **(click)**
- Once we have that next item, we can execute whatever the body of our `for` loop is supposed to do **(click)**
- And if we get a `StopIteration` exception while we're asking for the next item **(click)**, we know it's time to stop looping *(pause)*
- **(click)** We've just re-invented a `for` loop by using a `while` loop and iterators
- This code pretty much defines the way looping works under the hood in Python
- If you understand the way the built-in `iter` and `next` functions work for looping over things, you understand how Python's `for` loops work
The Iterator Protocol
for n in numbers:
print(n)
x, y, z = coordinates
a, b, *rest = numbers
print(*numbers)
unique_numbers = set(numbers)
- In fact this is a little bit more than just how `for` loops work.
- **The iterator protocol** is a very fancy sounding way of saying "how looping works in Python"
- It's essentially the definition of the way the `iter` and `next` functions work in Python, which is what we just saw
- The iterator protocol is the thing that powers *all* forms of iteration in Python
- **(click)** For loops use the iterator protocol
- **(click)** Multiple assignment also uses the iterator protol
- **(click)** star expressions use it
- **(click)** many built-in functions rely on the iterator protocol
- Anything in Python that works with an *iterable* probably uses the iterator protocol in some way
- Any time you're looping over an iterable, you're relying on the iterator protocol
I lied
- So I haven't quite been telling you the truth... at least not the whole truth
- There's something pretty *important* that I've neglected to mention so far...
Iterators are iterables
>>> numbers = [1, 2, 3]
>>> iterator = iter(numbers)
>>> iterator2 = iter(iterator)
>>> iterator2
<listiterator object at 0x7f92db9bf350>
>>> iterator is iterator2
True
- **Iterators** are also **iterables**
- Which means that we can get an iterator from an *iterator* using the built-in `iter` function **(click)**
- Just like we can with any other iterable **(click)**
- So we can also call `iter` on an *iterator* to ask **it** for an iterator
- When we *do that* **(click)** , it will give us **itself** back **(click)**
- Iterators are iterables and their iterator is themselves
- Iterators are their own iterators
Iterators are their own iterators
def is_iterator(iterable):
return iter(iterable) is iterable
- This fact that I've neglected to mention so far, that iterators are also iterables... this is the last key part of Python's **iterator protocol**
- If you ask an iterable for an iterator and it gives you *itself* back, that iterable **must** be also an iterator
- All iterators are iterables
- And all iterators are their own iterators
- Who's confused right now?
- Who wants me to say the words iterator and iterable a few more times?
- The similarity between these words makes talking about these stuff a little confusing sometimes
- So iterables are something you can loop over.
- Iterators are the thing that helps you loop over an iterable.
- But iterators are *also* something you can loop over. All iterators are also iterables.
- Let's talk about why that matters
Iterators are single-purposed
>>> numbers = [1, 2, 3, 5, 7]
>>> iterator = iter(numbers)
>>> len(iterator)
TypeError: object of type 'list_iterator' has no len()
>>> iterator[0]
TypeError: 'list_iterator' object is not subscriptable
>>> next(iterator)
1
>>> list(iterator)
[2, 3, 5, 7]
>>> list(iterator)
[]
- So iterators are iterables, but they have no idea how many items they contain
- **(click)** So they have no length
- **(click)** They also can't be indexed
- The only things you can do with iterators are:
- call `next` on them **(click)**
- and loop over them **(click)**
- And if we loop over an iterator a second time, we'll get nothing back **(click)**
- You can think of iterators are **lazy iterables** that can be looped over **one time only**
- Iterators are lazy iterables that can *only* be looped over once, and then they're done
The truth
Object
Iterable?
Iterator?
Iterable ✔ ❓
Iterator ✔ ✔
Generator ✔ ✔
List ✔ ❌
- So some quick review
- So iterables are not necessarily iterators
- But iterators are always iterables
- For example generators are iterators
- But lists are not iterators
- Iterables are not *always* iterators, but iterators *are* always iterables
So...why do we care?
- Okay this is all a little bit confusing
- And I still haven't really answered the question of...
- Do we really need to know any of this?
Iterators enable laziness
Iterators allow for lazily evaluated iterables
Iterators allow for infinitely long iterables
Iterators allow us to save memory and (sometimes) time
- So there are some very good reasons for understanding the iterator protocol in Python
- **(click)** Understanding iterators will allow *you* to be lazy and they will allow *your code* to be lazy
- Iterators allow us to both *work with* and *create* **lazy iterables** that don't do *any work* until we *ask them* for their **next item**
- **(click)** Because we can create lazy iterables, we can make **infinitely long** iterables
- **(click)** And we can create iterables that are conservative with system resources, that save us memory of save us time
Iterators are everywhere
>>> letters = ['a', 'b']
>>> next(enumerate(letters))
(0, 'a')
>>> next(zip(letters, letters))
('a', 'a')
>>> next(open('hello.txt'))
'hello world\n'
- You've already seen lots of iterators in Python
- I've already mentioned that generators are iterators
- **(click)** `enumerate` objects are also iterators
- **(click)** and so are `zip` objects
- **(click)** and a number of other objects including files
- There are lots of iterators built-in to Python, in the standard library, and in third-party libraries that you use all the time
- These iterators **all** act like **lazy iterables**
- They don't do any work, until you start looping them
Creating your own iterator
class square_all:
def __init__(self, numbers):
self.numbers = iter(numbers)
def __next__(self):
return next(self.numbers) ** 2
def __iter__(self):
return self
def square_all(numbers):
for n in numbers:
yield n**2
def square_all(numbers):
return (n**2 for n in numbers)
- So it's useful to know that you're already using iterators
- But I'd like you to know that you can use iterators to create *your own* lazy iterables **(click)**
- This class makes an iterator that accepts an *iterable of numbers* and squares each of those numbers
- but it doesn't do any work until we start looping over it
- This iterator works, but we *don't* usually make iterators this way with classes
- Usually when we want to make a custom iterator, we make a generator function **(click)**
- This generator function is equivalent to that class
- *(pause)* That `yield` statement probably seem magical, but it is *very* powerful: that `yield` allows us to put our generator on pause between `next` calls
- *(pause)* Another way we could implement this same iterator is with a generator expression **(click)**
- This does the same thing as that generator function but it uses a syntax that looks like a list comprehension
- If you need to make a lazy iterable, think of iterators... and consider making a generator function or a generator expression
think lazy
hours_worked = 0
for event in events:
if event.is_billable():
hours_worked += event.duration
billable_times = (
event.duration
for event in events
if event.is_billable()
)
hours_worked = sum(billable_times)
- once you've embraced the idea of lazy iterables, you'll find that there are lots of possibilities for discovering or creating helper functions that assist you in looping over iterables and processing data
- **(click)** This is a for loop that sums up all billable hours in a Django queryset
- **(click)** This is the same thing using a generator expression for lazy evaluation
- These two blocks of code do the same thing
- Notice that the structure of this code is fundamentally different
- We're able to use the `sum` function in the bottom example because we have a lazy iterable to work with
- Iterators allow you to fundamentally change the way you structure your code
Think lazy
for i, line in enumerate(log_file):
if i >= 10:
break
print(line)
from itertools import islice
first_ten_lines = islice(log_file, 10)
for line in first_ten_lines:
print(line)
- **[20 MINUTES]**
- **(click)** This code prints out the first ten lines of a log file
- **(click)** This code does the same thing
- That `first_ten_lines` thing is an iterator
- This iterator allowed us to *name* something that **didn't previously have a name**ng
- We've given a variable name to `first_ten_lines`, which makes our code more descriptive
- We've also gotten rid of the need for that ugly `break` statement we had in our first loop
Think Lazy
previous = readings[0]
for current in readings[1:]:
differences.append(current - previous)
previous = current
from my_fancy_utils_module import with_previous
differences = []
for previous, current in with_previous(readings):
differences.append(current - previous)
- **(click)** This code makes a list of the differences between consecutive values in a sequence
- Notice that this code has an extra variable that we need to assign each time we loop
- **(click)** This is the same code but we're using a generator function that we made up
- Notice that this code doesn't have awkward variable assignments hanging around our loop... the `with_previous` generator function handles that for us
THINK LAZY
def with_previous(iterable):
"""Yield (previous, current) tuples, starting with second."""
iterator = iter(iterable)
previous = next(iterator)
for item in iterator:
yield previous, item
previous = item
- In case you're curious what that mysterious generator function looks like, here's a plausible version of it
- Notice that we're manually getting an iterator from our iterable and calling `next` on it to grab the first item.
- This function works not just with sequences, but with any type of iterable
- I'm not going to step through this. You can take a closer look on my slides later.
Looping Problems
Revisited
- At this point we're ready to jump back **(click)** to those odd examples we saw earlier and try to figure out what was going on
Exhausted
Looping Twice
>>> numbers = [1, 2, 3, 5, 7]
>>> squares = (n**2 for n in numbers)
>>> tuple(squares)
(1, 4, 9, 25, 49)
>>> sum(squares)
0
>>> tuple(squares)
()
- Here we have a generator object, `squares`
- If we pass this generator to the `tuple` constructor **(click)**, we'll get a tuple of its items back **(click)**
- If we then try to compute the `sum` of the numbers in this generator **(click)**, we'll get `0` **(click)**
- This generator is now empty: we've exhausted it **(click)**
- If we try to make a tuple out of it again **(click)**, we'll get an empty tuple **(click)**
- Generators are iterators
- And recall that iterators are like Hello Kitty PEZ dispensers that cannot be reloaded
- Once we run out of PEZ, the dispenser is forever empty
Partially-Consumed
Containment Checking
>>> numbers = [1, 2, 3, 5, 7]
>>> squares = (n**2 for n in numbers)
>>> 9 in squares
True
>>> 9 in squares
False
>>> squares = (n**2 for n in numbers)
>>> 9 in squares
True
>>> list(squares)
[25, 49]
- If we ask whether `9` is in this `squares` generator **(click)**, we'll get `True` **(click)**
- If we ask the same question again **(click)**, we'll get `False` **(click)**
- When we ask whether `9` is in this generator, Python has to loop over this generator to find `9` **(click)**
- If we kept looping over it after checking for `9`, we'll only get the last two numbers because we've already consumed the numbers before this point **(click)**
- Asking whether something is *contained* in an iterator will partially consume the iterator **(click)**
- *Remember* that iterators are like one-directional tally-counters without a reset button
- There is no way to know whether something is in an iterator without starting to loop over it
Unpacking
>>> counts = {'apples': 2, 'oranges': 1}
>>> for key in counts:
... print(key)
...
apples
oranges
>>> x, y = counts
>>> x, y
('apples', 'oranges')
- When you *loop* over dictionaries **(click)** you get keys **(click)**
- Looping relies on the iterator protocol
- Iterable unpacking also relies on the iterator protocol **(click)**
- Unpacking a dictionary is really the same as looping over the dictionary **(click)**
- Both use the iterator protocol, so you get the same result in both cases


We offer the best online customer-friendly services. With our diligent staffs and personnels who work tirelessly to match the everyday needs of our dear customers, a team of well-equipped programmers who create server-friendly and proper sites using clean codes. We engage in facets such as online gaming, food delivery, online stores and so much more. We promise to provide top-notch service to our esteemed customers, both present and future.


Opinion
AMERICAN TRUCKING ASSOCIATIONS, INC.
<fs fs="11">and
USF HOLLAND, INC., PETITIONERS
v.
MICHIGAN
PUBLIC SERVICE COMMISSION et al.
Justice Breyer delivered the opinion of the Court.
In this case, we consider whether a flat $100 fee that Michigan charges trucks engaging in intrastate commercial hauling violates the dormant Commerce Clause. We hold that it does not.
I
A subsection of Michigans Motor Carrier Act imposes upon each motor carrier for the administration of this act, an annual fee of $100.00 for each self-propelled motor vehicle operated by or on behalf of the motor carrier. Mich. Comp. Laws Ann. §478.2(1) (West 2002). The provision assesses the fee upon, and only upon, vehicles that engage in intrastate commercial operationsthat is, on trucks that undertake point-to-point hauls between Michigan cities. See Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , 255 Mich. App. 589, 592594, 662 N. W. 2d 784, 789 (2003). Petitioners, USF Holland, Inc., a trucking company with trucks that engage in both interstate and intrastate hauling, and the American Trucking Associations, Inc. (ATA), asked the Michigan courts to invalidate the provision. Both petitioners told those courts that trucks that carry both interstate and intrastate loads engage in intrastate business less than trucks that confine their operations to the Great Lakes State. Hence, because Michigans fee is flat, it discriminates against interstate carriers and imposes an unconstitutional burden upon interstate trade.
The Michigan Court of Claims rejected the carriers claim for three reasons. First, the $100 fee is regulatory and intended for the Motor Carrier Acts administration, which includes regulation of vehicular size and weight, insurance requirements and safety standards. App. to Pet. for Cert. 44a. Such a fee is not amenable to a fee structure based on apportionment by usage rates. Ibid. Second, the fee reflects a legitimate expression of the [S]tates concern that the welfare of its citizens be protected, and hence an appropriate exercise of the States police power. Ibid. Third, the fee does not implicate the Commerce Clause because it falls only on intrastate, not interstate, commerce. Id. , at 45a.
The Michigan Court of Appeals affirmed. It did not agree that the intrastate nature of §478.2(1) sheltered the fee from Commerce Clause scrutiny. 255 Mich. App., at 617619 , 662 N. W. 2d, at 802. Nonetheless, the court rejected the truckers claim because the statute regulates evenhandedly, id. , at 621, 662 N. W. 2d, at 804, and because the record lacked any evidence that any trucking firms route choices [were] affected by the imposition of the fee, id. , at 621, 662 N. W. 2d, at 803804. Rather, the record indicated that any effect . . . on interstate commerce is incidental, rendering the truckers claim of discrimination a matter of pure speculation. Ibid.
The Michigan Supreme Court denied petitioners leave to appeal. Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , ___ Mich. ___, 673 N. W. 2d 752 (2003). We granted their petition for certiorari and consolidated the case with Mid-Con Freight Systems, Inc. v. Michigan Pub. Serv. Commn , No. 031234, a case in which interstate truckers sought review of a separate state motor carrier fee. We now affirm the Michigan courts judgment sustaining §478.2(1).
II
Our Constitution was framed upon the theory that the peoples of the several states must sink or swim together. Baldwin v. G. A. F. Seelig, Inc., 294 U. S. 511, 523 (1935) . Thus, this Court has consistently held that the Constitutions express grant to Congress of the power to regulate Commerce . . . among the several States, Art. I, §8, cl. 3, contains a further, negative command, known as the dormant Commerce Clause, Oklahoma Tax Commn v. Jefferson Lines, Inc. , 514 U. S. 175, 179 (1995) , that create[s] an area of trade free from interference by the States, Boston Stock Exchange v. State Tax Commn, 429 U. S. 318, 328 (1977) (internal quotation marks omitted). This negative command prevents a State from jeopardizing the welfare of the Nation as a whole by plac[ing] burdens on the flow of commerce across its borders that commerce wholly within those borders would not bear. Jefferson Lines, supra , at 180.
Thus, we have found unconstitutional state regulations that unjustifiably discriminate on their face against out-of-state entities, see Philadelphia v. New Jersey, 437 U. S. 617 (1978) , or that impose burdens on interstate trade that are clearly excessive in relation to the putative local benefits, Pike v. Bruce Church, Inc., 397 U. S. 137, 142 (1970) . We have held that States may not impose taxes that facially discriminate against interstate business and offer commercial advantage to local enterprises, see, e.g., Oregon Waste Systems, Inc. v. Department of Environmental Quality of Ore., 511 U. S. 93, 99100 (1994) , that improperly apportion state assessments on transactions with out-of-state components, Central Greyhound Lines, Inc. v. Mealey, 334 U. S. 653 (1948) , or that have the inevitable effect [of] threaten[ing] the free movement of commerce by placing a financial barrier around the State, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266, 284 (1987) .
Applying these principles and precedents, we find nothing in §478.2(1) that offends the Commerce Clause. To begin with, Michigan imposes the flat $100 fee only upon intrastate transactionsthat is, upon activities taking place exclusively within the States borders. Section 478.2(1) does not facially discriminate against interstate or out-of-state activities or enterprises. The statute applies evenhandedly to all carriers that make domestic journeys. It does not reflect an effort to tax activity that takes place, in whole or in part, outside the State. Nothing in our case law suggests that such a neutral, locally focused fee or tax is inconsistent with the dormant Commerce Clause.
This legal vacuum is not surprising. States impose numerous flat fees upon local businesses and service providers, including, for example, upon insurers, auctioneers, ambulance operators, and hosts of others. See, e.g., Wyo. Stat. §3336104 (Lexis 2003); S. C. Code Ann. §38710 (West 2002). Although we have long since rejected any suggestion that a state tax … affecting interstate commerce is immune from Commerce Clause scrutiny because it attaches only to a local or intrastate activity, Commonwealth Edison Co. v. Montana , 453 U. S. 609, 615 (1981) , we have also made clear that the Constitution neither displaces States authority to shelter [their] people from menaces to their health or safety, D. H. Holmes Co. v. McNamara, 486 U. S. 24, 29 (1988) (internal quotation marks omitted), nor unduly curtail[s] States power to lay taxes for the support of state government, McGoldrick v. Berwind-White Coal Mining Co., 309 U. S. 33, 48 (1940) .
The record, moreover, shows no special circumstance suggesting that Michigans fee operates in practice as anything other than an unobjectionable exercise of the States police power. To the contrary, as the Michigan Court of Appeals pointed out, the record contains little, if any, evidence that the $100 fee imposes any significant practical burden upon interstate trade. See 255 Mich. App., at 620622 , 662 N. W. 2d, at 803804. The record does show, for example, that some interstate trucks top off some interstate hauls with intrastate pickups and deliveries. See Brief for Intervening Plaintiffs-Appellants in Nos. 226052, 226122 (Ct. App. Mich.), Exh. 3, Affidavit of James C. Crozier ¶7 (licensing and fuel manager of TNT Holland Motor Express, Inc. describing this practice). But it does not tell us the answers to such questions as: How often does topping off occur across the industry? Does the $100 charge make a difference by significantly discouraging interstate carriers from engaging in topping off? Does the possibility of obtaining a 72-hour intrastate permit for $10 alleviate the alleged problem? See §478.2(3); see also Brief for Respondents 2, n. 3 (4,928 temporary permits were issued in 2004). If the fees ($100 and $10) discourage topping off, does that local commercial effect make a significant interstate difference? Would a variable fee (of the kind the truckers advocate) eliminate such difference? The minimal facts in the record tell us little about these matters. Compare App. 6061, Supplemental Affidavit of Thomas R. Lonergan ¶10(e) (official of the Michigan Public Service Commission stating that topping off is rare for most interstate carriers because it disrupts schedules and shipping patterns), with Reply Brief for Intervening Plaintiffs-Appellants in Nos. 226122, 226137 (Ct. App. Mich.), Exh. A, Supplemental Affidavit of James C. Crozier ¶6 (TNT Holland frequently tops off interstate loads). And at oral argument, ATA conceded the absence of record facts that empirically could show that the $100 fee significantly deters interstate trade. Tr. of Oral Arg. 5.
Neither does the record show that the flat assessment unfairly discriminates against interstate truckers. The fee seeks to defray costs such as those of regulating vehicular size and weight, of administering insurance requirements, and of applying safety standards. App. to Pet. for Cert. 44a. The bulk of such costs would seem more likely to vary per truck or per carrier than to vary per-mile traveled. See 255 Mich. App., at 612617, 662 N. W. 2d, at 799801. And that fact means that a per-truck, rather than a per-mile, assessment is likely fair. Cf. Jefferson Lines , 514 U. S., at 199 (rejecting taxpayers discrimination claim in part because miles traveled within the State simply are not a relevant proxy for the benefit conferred upon the parties to a sales transaction). Nothing in the record suggests the contrary.
Nor would an effort to switch the manner of fee assessmentfrom lump sum to, for example, miles traveledbe burden free. The record contains an affidavit, sworn by a Michigan Public Service Commission official, that states that to obtain the same revenue (about $3.5 million) through a per-mile fee would require the State to create a data accumulation system capable of separating out intrastate hauls and determining their length, and to develop related liability, billing, and auditing mechanisms. App. 64, Second Supplemental Affidavit of Thomas R. Lonergan ¶2. This affidavit, on its face, suggests that the game is unlikely to be worth the candle. While petitioners argue the contrary, they do not provide the details of their preferred alternative administrative system nor point to record evidence showing its practicality. See Jefferson Lines , supra, at 195 (State is not required to use a particular apportionment formula just because it may be possible to do so).
Petitioners insist that they do not need empirically to demonstrate the existence of a burdensome or discriminatory impact upon interstate trucking, or (presumably) the unfairness of the assessment in relation to defrayed costs, or (presumably) the administrative practicality of the alternatives. They say that our earlier case, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266 (1987) , requires invalidation of the $100 flat fee, even in the absence of such proof. We disagree.
In Scheiner , this Court invalidated a flat $25 marker fee and a flat axle tax that Pennsylvania levied upon all trucks (interstate and intrastate) that used its roads, including trucks that merely crossed Pennsylvanias borders to transport, say, Ohio goods to New Jersey customers. See id., at 273275. Data showed that the fees imposed a cost per mile on interstate trucks that was approximately five times as heavy as the cost per mile borne by local trucks. Id. , at 286. The assessments largely helped to raise revenue to improve and maintain [the States] highways and bridges, id. , at 270, thereby helping to cover costs likely to vary significantly with truck-miles traveled, see ibid. And the assessments did not even purport to approximate fairly the cost or value of the use of Pennsylvanias roads. Id., at 290. In light of these considerations, Pennsylvanias lump-sum taxes threaten[ed] the free movement of commerce by placing a financial barrier around the State of Pennsylvania. Id. , at 284. We concluded that [i]f each State imposed flat taxes for the privilege of making commercial entrances into its territory, there [was] no conceivable doubt that commerce among the States would be deterred. Ibid.
The present fee, as we have said, taxes purely local activity; it does not tax an interstate trucks entry into the State nor does it tax transactions spanning multiple States. See 255 Mich. App., at 592594, 662 N. W. 2d, at 789. We lack convincing evidence showing that the tax deters, or for that matter discriminates against, interstate activities. See supra , at 5. Nor is the tax one that, on its face, would seem to call for an assessment measured per mile rather than per truck. See supra , at 6. Consequently, we lack any reason to infer that Michigans lump-sum levy erects, as in Scheiner, an impermissible discriminatory road block.
Petitioners add that Michigans fee fails the internal consistency testa test that we have typically used where taxation of interstate transactions are at issue. Generally speaking, that test asks, What would happen if all States did the same? See, e.g., Goldberg v. Sweet, 488 U. S. 252, 261 (1989) ; Jefferson Lines , supra, at 185 (test looks to the structure of the tax to see whether its identical application by every State would place interstate commerce at a disadvantage as compared with commerce intrastate). We must concede that here, as petitioners argue, if all States did the same, an interstate truck would have to pay fees totaling several hundred dollars, or even several thousand dollars, were it to top off its business by carrying local loads in many (or even all) other States. But it would have to do so only because it engages in local business in all those States. An interstate firm with local outlets normally expects to pay local fees that are uniformly assessed upon all those who engage in local business, interstate and domestic firms alike. See, e.g., Commonwealth Edison , 453 U. S., at 623624 (dormant Commerce Clause does not seek to relieve those engaged in interstate commerce from their just share of state tax burden even though it increases the cost of doing business (internal quotation marks omitted)); cf. Jefferson Lines , supra , at 187188 (in context of sales tax, the Commerce Clause does not forbid the actual assessment of a succession of taxes by different States on distinct events as the same tangible object flows along). A motor carrier is not special in this respect.
In sum, petitioners have failed to show that Michigans fee, which does not seek to tax a share of interstate transactions, which focuses upon local activity, and which is assessed evenhandedly, either burdens or discriminates against interstate commerce, or violates the Commerce Clause in any other relevant way. See Complete Auto Transit, Inc. v. Brady , 430 U. S. 274, 279 (1977) (noting that a tax will be sustained where it is applied to an activity with a substantial nexus to the taxing State; where, if applied to interstate activity, it is fairly apportioned; where it does not discriminate; and where it is fairly related to the services provided).
For these reasons, the judgment of the Michigan Court of Appeals is affirmed.
It is so ordered.
Opinion
AMERICAN TRUCKING ASSOCIATIONS, INC.
<fs fs="11">and
USF HOLLAND, INC., PETITIONERS
v.
MICHIGAN
PUBLIC SERVICE COMMISSION et al.
Justice Breyer delivered the opinion of the Court.
In this case, we consider whether a flat $100 fee that Michigan charges trucks engaging in intrastate commercial hauling violates the dormant Commerce Clause. We hold that it does not.
I
A subsection of Michigans Motor Carrier Act imposes upon each motor carrier for the administration of this act, an annual fee of $100.00 for each self-propelled motor vehicle operated by or on behalf of the motor carrier. Mich. Comp. Laws Ann. §478.2(1) (West 2002). The provision assesses the fee upon, and only upon, vehicles that engage in intrastate commercial operationsthat is, on trucks that undertake point-to-point hauls between Michigan cities. See Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , 255 Mich. App. 589, 592594, 662 N. W. 2d 784, 789 (2003). Petitioners, USF Holland, Inc., a trucking company with trucks that engage in both interstate and intrastate hauling, and the American Trucking Associations, Inc. (ATA), asked the Michigan courts to invalidate the provision. Both petitioners told those courts that trucks that carry both interstate and intrastate loads engage in intrastate business less than trucks that confine their operations to the Great Lakes State. Hence, because Michigans fee is flat, it discriminates against interstate carriers and imposes an unconstitutional burden upon interstate trade.
The Michigan Court of Claims rejected the carriers claim for three reasons. First, the $100 fee is regulatory and intended for the Motor Carrier Acts administration, which includes regulation of vehicular size and weight, insurance requirements and safety standards. App. to Pet. for Cert. 44a. Such a fee is not amenable to a fee structure based on apportionment by usage rates. Ibid. Second, the fee reflects a legitimate expression of the [S]tates concern that the welfare of its citizens be protected, and hence an appropriate exercise of the States police power. Ibid. Third, the fee does not implicate the Commerce Clause because it falls only on intrastate, not interstate, commerce. Id. , at 45a.
The Michigan Court of Appeals affirmed. It did not agree that the intrastate nature of §478.2(1) sheltered the fee from Commerce Clause scrutiny. 255 Mich. App., at 617619 , 662 N. W. 2d, at 802. Nonetheless, the court rejected the truckers claim because the statute regulates evenhandedly, id. , at 621, 662 N. W. 2d, at 804, and because the record lacked any evidence that any trucking firms route choices [were] affected by the imposition of the fee, id. , at 621, 662 N. W. 2d, at 803804. Rather, the record indicated that any effect . . . on interstate commerce is incidental, rendering the truckers claim of discrimination a matter of pure speculation. Ibid.
The Michigan Supreme Court denied petitioners leave to appeal. Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , ___ Mich. ___, 673 N. W. 2d 752 (2003). We granted their petition for certiorari and consolidated the case with Mid-Con Freight Systems, Inc. v. Michigan Pub. Serv. Commn , No. 031234, a case in which interstate truckers sought review of a separate state motor carrier fee. We now affirm the Michigan courts judgment sustaining §478.2(1).
II
Our Constitution was framed upon the theory that the peoples of the several states must sink or swim together. Baldwin v. G. A. F. Seelig, Inc., 294 U. S. 511, 523 (1935) . Thus, this Court has consistently held that the Constitutions express grant to Congress of the power to regulate Commerce . . . among the several States, Art. I, §8, cl. 3, contains a further, negative command, known as the dormant Commerce Clause, Oklahoma Tax Commn v. Jefferson Lines, Inc. , 514 U. S. 175, 179 (1995) , that create[s] an area of trade free from interference by the States, Boston Stock Exchange v. State Tax Commn, 429 U. S. 318, 328 (1977) (internal quotation marks omitted). This negative command prevents a State from jeopardizing the welfare of the Nation as a whole by plac[ing] burdens on the flow of commerce across its borders that commerce wholly within those borders would not bear. Jefferson Lines, supra , at 180.
Thus, we have found unconstitutional state regulations that unjustifiably discriminate on their face against out-of-state entities, see Philadelphia v. New Jersey, 437 U. S. 617 (1978) , or that impose burdens on interstate trade that are clearly excessive in relation to the putative local benefits, Pike v. Bruce Church, Inc., 397 U. S. 137, 142 (1970) . We have held that States may not impose taxes that facially discriminate against interstate business and offer commercial advantage to local enterprises, see, e.g., Oregon Waste Systems, Inc. v. Department of Environmental Quality of Ore., 511 U. S. 93, 99100 (1994) , that improperly apportion state assessments on transactions with out-of-state components, Central Greyhound Lines, Inc. v. Mealey, 334 U. S. 653 (1948) , or that have the inevitable effect [of] threaten[ing] the free movement of commerce by placing a financial barrier around the State, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266, 284 (1987) .
Applying these principles and precedents, we find nothing in §478.2(1) that offends the Commerce Clause. To begin with, Michigan imposes the flat $100 fee only upon intrastate transactionsthat is, upon activities taking place exclusively within the States borders. Section 478.2(1) does not facially discriminate against interstate or out-of-state activities or enterprises. The statute applies evenhandedly to all carriers that make domestic journeys. It does not reflect an effort to tax activity that takes place, in whole or in part, outside the State. Nothing in our case law suggests that such a neutral, locally focused fee or tax is inconsistent with the dormant Commerce Clause.
This legal vacuum is not surprising. States impose numerous flat fees upon local businesses and service providers, including, for example, upon insurers, auctioneers, ambulance operators, and hosts of others. See, e.g., Wyo. Stat. §3336104 (Lexis 2003); S. C. Code Ann. §38710 (West 2002). Although we have long since rejected any suggestion that a state tax … affecting interstate commerce is immune from Commerce Clause scrutiny because it attaches only to a local or intrastate activity, Commonwealth Edison Co. v. Montana , 453 U. S. 609, 615 (1981) , we have also made clear that the Constitution neither displaces States authority to shelter [their] people from menaces to their health or safety, D. H. Holmes Co. v. McNamara, 486 U. S. 24, 29 (1988) (internal quotation marks omitted), nor unduly curtail[s] States power to lay taxes for the support of state government, McGoldrick v. Berwind-White Coal Mining Co., 309 U. S. 33, 48 (1940) .
The record, moreover, shows no special circumstance suggesting that Michigans fee operates in practice as anything other than an unobjectionable exercise of the States police power. To the contrary, as the Michigan Court of Appeals pointed out, the record contains little, if any, evidence that the $100 fee imposes any significant practical burden upon interstate trade. See 255 Mich. App., at 620622 , 662 N. W. 2d, at 803804. The record does show, for example, that some interstate trucks top off some interstate hauls with intrastate pickups and deliveries. See Brief for Intervening Plaintiffs-Appellants in Nos. 226052, 226122 (Ct. App. Mich.), Exh. 3, Affidavit of James C. Crozier ¶7 (licensing and fuel manager of TNT Holland Motor Express, Inc. describing this practice). But it does not tell us the answers to such questions as: How often does topping off occur across the industry? Does the $100 charge make a difference by significantly discouraging interstate carriers from engaging in topping off? Does the possibility of obtaining a 72-hour intrastate permit for $10 alleviate the alleged problem? See §478.2(3); see also Brief for Respondents 2, n. 3 (4,928 temporary permits were issued in 2004). If the fees ($100 and $10) discourage topping off, does that local commercial effect make a significant interstate difference? Would a variable fee (of the kind the truckers advocate) eliminate such difference? The minimal facts in the record tell us little about these matters. Compare App. 6061, Supplemental Affidavit of Thomas R. Lonergan ¶10(e) (official of the Michigan Public Service Commission stating that topping off is rare for most interstate carriers because it disrupts schedules and shipping patterns), with Reply Brief for Intervening Plaintiffs-Appellants in Nos. 226122, 226137 (Ct. App. Mich.), Exh. A, Supplemental Affidavit of James C. Crozier ¶6 (TNT Holland frequently tops off interstate loads). And at oral argument, ATA conceded the absence of record facts that empirically could show that the $100 fee significantly deters interstate trade. Tr. of Oral Arg. 5.
Neither does the record show that the flat assessment unfairly discriminates against interstate truckers. The fee seeks to defray costs such as those of regulating vehicular size and weight, of administering insurance requirements, and of applying safety standards. App. to Pet. for Cert. 44a. The bulk of such costs would seem more likely to vary per truck or per carrier than to vary per-mile traveled. See 255 Mich. App., at 612617, 662 N. W. 2d, at 799801. And that fact means that a per-truck, rather than a per-mile, assessment is likely fair. Cf. Jefferson Lines , 514 U. S., at 199 (rejecting taxpayers discrimination claim in part because miles traveled within the State simply are not a relevant proxy for the benefit conferred upon the parties to a sales transaction). Nothing in the record suggests the contrary.
Nor would an effort to switch the manner of fee assessmentfrom lump sum to, for example, miles traveledbe burden free. The record contains an affidavit, sworn by a Michigan Public Service Commission official, that states that to obtain the same revenue (about $3.5 million) through a per-mile fee would require the State to create a data accumulation system capable of separating out intrastate hauls and determining their length, and to develop related liability, billing, and auditing mechanisms. App. 64, Second Supplemental Affidavit of Thomas R. Lonergan ¶2. This affidavit, on its face, suggests that the game is unlikely to be worth the candle. While petitioners argue the contrary, they do not provide the details of their preferred alternative administrative system nor point to record evidence showing its practicality. See Jefferson Lines , supra, at 195 (State is not required to use a particular apportionment formula just because it may be possible to do so).
Petitioners insist that they do not need empirically to demonstrate the existence of a burdensome or discriminatory impact upon interstate trucking, or (presumably) the unfairness of the assessment in relation to defrayed costs, or (presumably) the administrative practicality of the alternatives. They say that our earlier case, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266 (1987) , requires invalidation of the $100 flat fee, even in the absence of such proof. We disagree.
In Scheiner , this Court invalidated a flat $25 marker fee and a flat axle tax that Pennsylvania levied upon all trucks (interstate and intrastate) that used its roads, including trucks that merely crossed Pennsylvanias borders to transport, say, Ohio goods to New Jersey customers. See id., at 273275. Data showed that the fees imposed a cost per mile on interstate trucks that was approximately five times as heavy as the cost per mile borne by local trucks. Id. , at 286. The assessments largely helped to raise revenue to improve and maintain [the States] highways and bridges, id. , at 270, thereby helping to cover costs likely to vary significantly with truck-miles traveled, see ibid. And the assessments did not even purport to approximate fairly the cost or value of the use of Pennsylvanias roads. Id., at 290. In light of these considerations, Pennsylvanias lump-sum taxes threaten[ed] the free movement of commerce by placing a financial barrier around the State of Pennsylvania. Id. , at 284. We concluded that [i]f each State imposed flat taxes for the privilege of making commercial entrances into its territory, there [was] no conceivable doubt that commerce among the States would be deterred. Ibid.
The present fee, as we have said, taxes purely local activity; it does not tax an interstate trucks entry into the State nor does it tax transactions spanning multiple States. See 255 Mich. App., at 592594, 662 N. W. 2d, at 789. We lack convincing evidence showing that the tax deters, or for that matter discriminates against, interstate activities. See supra , at 5. Nor is the tax one that, on its face, would seem to call for an assessment measured per mile rather than per truck. See supra , at 6. Consequently, we lack any reason to infer that Michigans lump-sum levy erects, as in Scheiner, an impermissible discriminatory road block.
Petitioners add that Michigans fee fails the internal consistency testa test that we have typically used where taxation of interstate transactions are at issue. Generally speaking, that test asks, What would happen if all States did the same? See, e.g., Goldberg v. Sweet, 488 U. S. 252, 261 (1989) ; Jefferson Lines , supra, at 185 (test looks to the structure of the tax to see whether its identical application by every State would place interstate commerce at a disadvantage as compared with commerce intrastate). We must concede that here, as petitioners argue, if all States did the same, an interstate truck would have to pay fees totaling several hundred dollars, or even several thousand dollars, were it to top off its business by carrying local loads in many (or even all) other States. But it would have to do so only because it engages in local business in all those States. An interstate firm with local outlets normally expects to pay local fees that are uniformly assessed upon all those who engage in local business, interstate and domestic firms alike. See, e.g., Commonwealth Edison , 453 U. S., at 623624 (dormant Commerce Clause does not seek to relieve those engaged in interstate commerce from their just share of state tax burden even though it increases the cost of doing business (internal quotation marks omitted)); cf. Jefferson Lines , supra , at 187188 (in context of sales tax, the Commerce Clause does not forbid the actual assessment of a succession of taxes by different States on distinct events as the same tangible object flows along). A motor carrier is not special in this respect.
In sum, petitioners have failed to show that Michigans fee, which does not seek to tax a share of interstate transactions, which focuses upon local activity, and which is assessed evenhandedly, either burdens or discriminates against interstate commerce, or violates the Commerce Clause in any other relevant way. See Complete Auto Transit, Inc. v. Brady , 430 U. S. 274, 279 (1977) (noting that a tax will be sustained where it is applied to an activity with a substantial nexus to the taxing State; where, if applied to interstate activity, it is fairly apportioned; where it does not discriminate; and where it is fairly related to the services provided).
For these reasons, the judgment of the Michigan Court of Appeals is affirmed.
It is so ordered.
Opinion
AMERICAN TRUCKING ASSOCIATIONS, INC.
<fs fs="11">and
USF HOLLAND, INC., PETITIONERS
v.
MICHIGAN
PUBLIC SERVICE COMMISSION et al.
Justice Breyer delivered the opinion of the Court.
In this case, we consider whether a flat $100 fee that Michigan charges trucks engaging in intrastate commercial hauling violates the dormant Commerce Clause. We hold that it does not.
I
A subsection of Michigans Motor Carrier Act imposes upon each motor carrier for the administration of this act, an annual fee of $100.00 for each self-propelled motor vehicle operated by or on behalf of the motor carrier. Mich. Comp. Laws Ann. §478.2(1) (West 2002). The provision assesses the fee upon, and only upon, vehicles that engage in intrastate commercial operationsthat is, on trucks that undertake point-to-point hauls between Michigan cities. See Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , 255 Mich. App. 589, 592594, 662 N. W. 2d 784, 789 (2003). Petitioners, USF Holland, Inc., a trucking company with trucks that engage in both interstate and intrastate hauling, and the American Trucking Associations, Inc. (ATA), asked the Michigan courts to invalidate the provision. Both petitioners told those courts that trucks that carry both interstate and intrastate loads engage in intrastate business less than trucks that confine their operations to the Great Lakes State. Hence, because Michigans fee is flat, it discriminates against interstate carriers and imposes an unconstitutional burden upon interstate trade.
The Michigan Court of Claims rejected the carriers claim for three reasons. First, the $100 fee is regulatory and intended for the Motor Carrier Acts administration, which includes regulation of vehicular size and weight, insurance requirements and safety standards. App. to Pet. for Cert. 44a. Such a fee is not amenable to a fee structure based on apportionment by usage rates. Ibid. Second, the fee reflects a legitimate expression of the [S]tates concern that the welfare of its citizens be protected, and hence an appropriate exercise of the States police power. Ibid. Third, the fee does not implicate the Commerce Clause because it falls only on intrastate, not interstate, commerce. Id. , at 45a.
The Michigan Court of Appeals affirmed. It did not agree that the intrastate nature of §478.2(1) sheltered the fee from Commerce Clause scrutiny. 255 Mich. App., at 617619 , 662 N. W. 2d, at 802. Nonetheless, the court rejected the truckers claim because the statute regulates evenhandedly, id. , at 621, 662 N. W. 2d, at 804, and because the record lacked any evidence that any trucking firms route choices [were] affected by the imposition of the fee, id. , at 621, 662 N. W. 2d, at 803804. Rather, the record indicated that any effect . . . on interstate commerce is incidental, rendering the truckers claim of discrimination a matter of pure speculation. Ibid.
The Michigan Supreme Court denied petitioners leave to appeal. Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , ___ Mich. ___, 673 N. W. 2d 752 (2003). We granted their petition for certiorari and consolidated the case with Mid-Con Freight Systems, Inc. v. Michigan Pub. Serv. Commn , No. 031234, a case in which interstate truckers sought review of a separate state motor carrier fee. We now affirm the Michigan courts judgment sustaining §478.2(1).
II
Our Constitution was framed upon the theory that the peoples of the several states must sink or swim together. Baldwin v. G. A. F. Seelig, Inc., 294 U. S. 511, 523 (1935) . Thus, this Court has consistently held that the Constitutions express grant to Congress of the power to regulate Commerce . . . among the several States, Art. I, §8, cl. 3, contains a further, negative command, known as the dormant Commerce Clause, Oklahoma Tax Commn v. Jefferson Lines, Inc. , 514 U. S. 175, 179 (1995) , that create[s] an area of trade free from interference by the States, Boston Stock Exchange v. State Tax Commn, 429 U. S. 318, 328 (1977) (internal quotation marks omitted). This negative command prevents a State from jeopardizing the welfare of the Nation as a whole by plac[ing] burdens on the flow of commerce across its borders that commerce wholly within those borders would not bear. Jefferson Lines, supra , at 180.
Thus, we have found unconstitutional state regulations that unjustifiably discriminate on their face against out-of-state entities, see Philadelphia v. New Jersey, 437 U. S. 617 (1978) , or that impose burdens on interstate trade that are clearly excessive in relation to the putative local benefits, Pike v. Bruce Church, Inc., 397 U. S. 137, 142 (1970) . We have held that States may not impose taxes that facially discriminate against interstate business and offer commercial advantage to local enterprises, see, e.g., Oregon Waste Systems, Inc. v. Department of Environmental Quality of Ore., 511 U. S. 93, 99100 (1994) , that improperly apportion state assessments on transactions with out-of-state components, Central Greyhound Lines, Inc. v. Mealey, 334 U. S. 653 (1948) , or that have the inevitable effect [of] threaten[ing] the free movement of commerce by placing a financial barrier around the State, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266, 284 (1987) .
Applying these principles and precedents, we find nothing in §478.2(1) that offends the Commerce Clause. To begin with, Michigan imposes the flat $100 fee only upon intrastate transactionsthat is, upon activities taking place exclusively within the States borders. Section 478.2(1) does not facially discriminate against interstate or out-of-state activities or enterprises. The statute applies evenhandedly to all carriers that make domestic journeys. It does not reflect an effort to tax activity that takes place, in whole or in part, outside the State. Nothing in our case law suggests that such a neutral, locally focused fee or tax is inconsistent with the dormant Commerce Clause.
This legal vacuum is not surprising. States impose numerous flat fees upon local businesses and service providers, including, for example, upon insurers, auctioneers, ambulance operators, and hosts of others. See, e.g., Wyo. Stat. §3336104 (Lexis 2003); S. C. Code Ann. §38710 (West 2002). Although we have long since rejected any suggestion that a state tax … affecting interstate commerce is immune from Commerce Clause scrutiny because it attaches only to a local or intrastate activity, Commonwealth Edison Co. v. Montana , 453 U. S. 609, 615 (1981) , we have also made clear that the Constitution neither displaces States authority to shelter [their] people from menaces to their health or safety, D. H. Holmes Co. v. McNamara, 486 U. S. 24, 29 (1988) (internal quotation marks omitted), nor unduly curtail[s] States power to lay taxes for the support of state government, McGoldrick v. Berwind-White Coal Mining Co., 309 U. S. 33, 48 (1940) .
The record, moreover, shows no special circumstance suggesting that Michigans fee operates in practice as anything other than an unobjectionable exercise of the States police power. To the contrary, as the Michigan Court of Appeals pointed out, the record contains little, if any, evidence that the $100 fee imposes any significant practical burden upon interstate trade. See 255 Mich. App., at 620622 , 662 N. W. 2d, at 803804. The record does show, for example, that some interstate trucks top off some interstate hauls with intrastate pickups and deliveries. See Brief for Intervening Plaintiffs-Appellants in Nos. 226052, 226122 (Ct. App. Mich.), Exh. 3, Affidavit of James C. Crozier ¶7 (licensing and fuel manager of TNT Holland Motor Express, Inc. describing this practice). But it does not tell us the answers to such questions as: How often does topping off occur across the industry? Does the $100 charge make a difference by significantly discouraging interstate carriers from engaging in topping off? Does the possibility of obtaining a 72-hour intrastate permit for $10 alleviate the alleged problem? See §478.2(3); see also Brief for Respondents 2, n. 3 (4,928 temporary permits were issued in 2004). If the fees ($100 and $10) discourage topping off, does that local commercial effect make a significant interstate difference? Would a variable fee (of the kind the truckers advocate) eliminate such difference? The minimal facts in the record tell us little about these matters. Compare App. 6061, Supplemental Affidavit of Thomas R. Lonergan ¶10(e) (official of the Michigan Public Service Commission stating that topping off is rare for most interstate carriers because it disrupts schedules and shipping patterns), with Reply Brief for Intervening Plaintiffs-Appellants in Nos. 226122, 226137 (Ct. App. Mich.), Exh. A, Supplemental Affidavit of James C. Crozier ¶6 (TNT Holland frequently tops off interstate loads). And at oral argument, ATA conceded the absence of record facts that empirically could show that the $100 fee significantly deters interstate trade. Tr. of Oral Arg. 5.
Neither does the record show that the flat assessment unfairly discriminates against interstate truckers. The fee seeks to defray costs such as those of regulating vehicular size and weight, of administering insurance requirements, and of applying safety standards. App. to Pet. for Cert. 44a. The bulk of such costs would seem more likely to vary per truck or per carrier than to vary per-mile traveled. See 255 Mich. App., at 612617, 662 N. W. 2d, at 799801. And that fact means that a per-truck, rather than a per-mile, assessment is likely fair. Cf. Jefferson Lines , 514 U. S., at 199 (rejecting taxpayers discrimination claim in part because miles traveled within the State simply are not a relevant proxy for the benefit conferred upon the parties to a sales transaction). Nothing in the record suggests the contrary.
Nor would an effort to switch the manner of fee assessmentfrom lump sum to, for example, miles traveledbe burden free. The record contains an affidavit, sworn by a Michigan Public Service Commission official, that states that to obtain the same revenue (about $3.5 million) through a per-mile fee would require the State to create a data accumulation system capable of separating out intrastate hauls and determining their length, and to develop related liability, billing, and auditing mechanisms. App. 64, Second Supplemental Affidavit of Thomas R. Lonergan ¶2. This affidavit, on its face, suggests that the game is unlikely to be worth the candle. While petitioners argue the contrary, they do not provide the details of their preferred alternative administrative system nor point to record evidence showing its practicality. See Jefferson Lines , supra, at 195 (State is not required to use a particular apportionment formula just because it may be possible to do so).
Petitioners insist that they do not need empirically to demonstrate the existence of a burdensome or discriminatory impact upon interstate trucking, or (presumably) the unfairness of the assessment in relation to defrayed costs, or (presumably) the administrative practicality of the alternatives. They say that our earlier case, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266 (1987) , requires invalidation of the $100 flat fee, even in the absence of such proof. We disagree.
In Scheiner , this Court invalidated a flat $25 marker fee and a flat axle tax that Pennsylvania levied upon all trucks (interstate and intrastate) that used its roads, including trucks that merely crossed Pennsylvanias borders to transport, say, Ohio goods to New Jersey customers. See id., at 273275. Data showed that the fees imposed a cost per mile on interstate trucks that was approximately five times as heavy as the cost per mile borne by local trucks. Id. , at 286. The assessments largely helped to raise revenue to improve and maintain [the States] highways and bridges, id. , at 270, thereby helping to cover costs likely to vary significantly with truck-miles traveled, see ibid. And the assessments did not even purport to approximate fairly the cost or value of the use of Pennsylvanias roads. Id., at 290. In light of these considerations, Pennsylvanias lump-sum taxes threaten[ed] the free movement of commerce by placing a financial barrier around the State of Pennsylvania. Id. , at 284. We concluded that [i]f each State imposed flat taxes for the privilege of making commercial entrances into its territory, there [was] no conceivable doubt that commerce among the States would be deterred. Ibid.
The present fee, as we have said, taxes purely local activity; it does not tax an interstate trucks entry into the State nor does it tax transactions spanning multiple States. See 255 Mich. App., at 592594, 662 N. W. 2d, at 789. We lack convincing evidence showing that the tax deters, or for that matter discriminates against, interstate activities. See supra , at 5. Nor is the tax one that, on its face, would seem to call for an assessment measured per mile rather than per truck. See supra , at 6. Consequently, we lack any reason to infer that Michigans lump-sum levy erects, as in Scheiner, an impermissible discriminatory road block.
Petitioners add that Michigans fee fails the internal consistency testa test that we have typically used where taxation of interstate transactions are at issue. Generally speaking, that test asks, What would happen if all States did the same? See, e.g., Goldberg v. Sweet, 488 U. S. 252, 261 (1989) ; Jefferson Lines , supra, at 185 (test looks to the structure of the tax to see whether its identical application by every State would place interstate commerce at a disadvantage as compared with commerce intrastate). We must concede that here, as petitioners argue, if all States did the same, an interstate truck would have to pay fees totaling several hundred dollars, or even several thousand dollars, were it to top off its business by carrying local loads in many (or even all) other States. But it would have to do so only because it engages in local business in all those States. An interstate firm with local outlets normally expects to pay local fees that are uniformly assessed upon all those who engage in local business, interstate and domestic firms alike. See, e.g., Commonwealth Edison , 453 U. S., at 623624 (dormant Commerce Clause does not seek to relieve those engaged in interstate commerce from their just share of state tax burden even though it increases the cost of doing business (internal quotation marks omitted)); cf. Jefferson Lines , supra , at 187188 (in context of sales tax, the Commerce Clause does not forbid the actual assessment of a succession of taxes by different States on distinct events as the same tangible object flows along). A motor carrier is not special in this respect.
In sum, petitioners have failed to show that Michigans fee, which does not seek to tax a share of interstate transactions, which focuses upon local activity, and which is assessed evenhandedly, either burdens or discriminates against interstate commerce, or violates the Commerce Clause in any other relevant way. See Complete Auto Transit, Inc. v. Brady , 430 U. S. 274, 279 (1977) (noting that a tax will be sustained where it is applied to an activity with a substantial nexus to the taxing State; where, if applied to interstate activity, it is fairly apportioned; where it does not discriminate; and where it is fairly related to the services provided).
For these reasons, the judgment of the Michigan Court of Appeals is affirmed.
It is so ordered.
Opinion
AMERICAN TRUCKING ASSOCIATIONS, INC.
<fs fs="11">and
USF HOLLAND, INC., PETITIONERS
v.
MICHIGAN
PUBLIC SERVICE COMMISSION et al.
Justice Breyer delivered the opinion of the Court.
In this case, we consider whether a flat $100 fee that Michigan charges trucks engaging in intrastate commercial hauling violates the dormant Commerce Clause. We hold that it does not.
I
A subsection of Michigans Motor Carrier Act imposes upon each motor carrier for the administration of this act, an annual fee of $100.00 for each self-propelled motor vehicle operated by or on behalf of the motor carrier. Mich. Comp. Laws Ann. §478.2(1) (West 2002). The provision assesses the fee upon, and only upon, vehicles that engage in intrastate commercial operationsthat is, on trucks that undertake point-to-point hauls between Michigan cities. See Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , 255 Mich. App. 589, 592594, 662 N. W. 2d 784, 789 (2003). Petitioners, USF Holland, Inc., a trucking company with trucks that engage in both interstate and intrastate hauling, and the American Trucking Associations, Inc. (ATA), asked the Michigan courts to invalidate the provision. Both petitioners told those courts that trucks that carry both interstate and intrastate loads engage in intrastate business less than trucks that confine their operations to the Great Lakes State. Hence, because Michigans fee is flat, it discriminates against interstate carriers and imposes an unconstitutional burden upon interstate trade.
The Michigan Court of Claims rejected the carriers claim for three reasons. First, the $100 fee is regulatory and intended for the Motor Carrier Acts administration, which includes regulation of vehicular size and weight, insurance requirements and safety standards. App. to Pet. for Cert. 44a. Such a fee is not amenable to a fee structure based on apportionment by usage rates. Ibid. Second, the fee reflects a legitimate expression of the [S]tates concern that the welfare of its citizens be protected, and hence an appropriate exercise of the States police power. Ibid. Third, the fee does not implicate the Commerce Clause because it falls only on intrastate, not interstate, commerce. Id. , at 45a.
The Michigan Court of Appeals affirmed. It did not agree that the intrastate nature of §478.2(1) sheltered the fee from Commerce Clause scrutiny. 255 Mich. App., at 617619 , 662 N. W. 2d, at 802. Nonetheless, the court rejected the truckers claim because the statute regulates evenhandedly, id. , at 621, 662 N. W. 2d, at 804, and because the record lacked any evidence that any trucking firms route choices [were] affected by the imposition of the fee, id. , at 621, 662 N. W. 2d, at 803804. Rather, the record indicated that any effect . . . on interstate commerce is incidental, rendering the truckers claim of discrimination a matter of pure speculation. Ibid.
The Michigan Supreme Court denied petitioners leave to appeal. Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , ___ Mich. ___, 673 N. W. 2d 752 (2003). We granted their petition for certiorari and consolidated the case with Mid-Con Freight Systems, Inc. v. Michigan Pub. Serv. Commn , No. 031234, a case in which interstate truckers sought review of a separate state motor carrier fee. We now affirm the Michigan courts judgment sustaining §478.2(1).
II
Our Constitution was framed upon the theory that the peoples of the several states must sink or swim together. Baldwin v. G. A. F. Seelig, Inc., 294 U. S. 511, 523 (1935) . Thus, this Court has consistently held that the Constitutions express grant to Congress of the power to regulate Commerce . . . among the several States, Art. I, §8, cl. 3, contains a further, negative command, known as the dormant Commerce Clause, Oklahoma Tax Commn v. Jefferson Lines, Inc. , 514 U. S. 175, 179 (1995) , that create[s] an area of trade free from interference by the States, Boston Stock Exchange v. State Tax Commn, 429 U. S. 318, 328 (1977) (internal quotation marks omitted). This negative command prevents a State from jeopardizing the welfare of the Nation as a whole by plac[ing] burdens on the flow of commerce across its borders that commerce wholly within those borders would not bear. Jefferson Lines, supra , at 180.
Thus, we have found unconstitutional state regulations that unjustifiably discriminate on their face against out-of-state entities, see Philadelphia v. New Jersey, 437 U. S. 617 (1978) , or that impose burdens on interstate trade that are clearly excessive in relation to the putative local benefits, Pike v. Bruce Church, Inc., 397 U. S. 137, 142 (1970) . We have held that States may not impose taxes that facially discriminate against interstate business and offer commercial advantage to local enterprises, see, e.g., Oregon Waste Systems, Inc. v. Department of Environmental Quality of Ore., 511 U. S. 93, 99100 (1994) , that improperly apportion state assessments on transactions with out-of-state components, Central Greyhound Lines, Inc. v. Mealey, 334 U. S. 653 (1948) , or that have the inevitable effect [of] threaten[ing] the free movement of commerce by placing a financial barrier around the State, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266, 284 (1987) .
Applying these principles and precedents, we find nothing in §478.2(1) that offends the Commerce Clause. To begin with, Michigan imposes the flat $100 fee only upon intrastate transactionsthat is, upon activities taking place exclusively within the States borders. Section 478.2(1) does not facially discriminate against interstate or out-of-state activities or enterprises. The statute applies evenhandedly to all carriers that make domestic journeys. It does not reflect an effort to tax activity that takes place, in whole or in part, outside the State. Nothing in our case law suggests that such a neutral, locally focused fee or tax is inconsistent with the dormant Commerce Clause.
This legal vacuum is not surprising. States impose numerous flat fees upon local businesses and service providers, including, for example, upon insurers, auctioneers, ambulance operators, and hosts of others. See, e.g., Wyo. Stat. §3336104 (Lexis 2003); S. C. Code Ann. §38710 (West 2002). Although we have long since rejected any suggestion that a state tax … affecting interstate commerce is immune from Commerce Clause scrutiny because it attaches only to a local or intrastate activity, Commonwealth Edison Co. v. Montana , 453 U. S. 609, 615 (1981) , we have also made clear that the Constitution neither displaces States authority to shelter [their] people from menaces to their health or safety, D. H. Holmes Co. v. McNamara, 486 U. S. 24, 29 (1988) (internal quotation marks omitted), nor unduly curtail[s] States power to lay taxes for the support of state government, McGoldrick v. Berwind-White Coal Mining Co., 309 U. S. 33, 48 (1940) .
The record, moreover, shows no special circumstance suggesting that Michigans fee operates in practice as anything other than an unobjectionable exercise of the States police power. To the contrary, as the Michigan Court of Appeals pointed out, the record contains little, if any, evidence that the $100 fee imposes any significant practical burden upon interstate trade. See 255 Mich. App., at 620622 , 662 N. W. 2d, at 803804. The record does show, for example, that some interstate trucks top off some interstate hauls with intrastate pickups and deliveries. See Brief for Intervening Plaintiffs-Appellants in Nos. 226052, 226122 (Ct. App. Mich.), Exh. 3, Affidavit of James C. Crozier ¶7 (licensing and fuel manager of TNT Holland Motor Express, Inc. describing this practice). But it does not tell us the answers to such questions as: How often does topping off occur across the industry? Does the $100 charge make a difference by significantly discouraging interstate carriers from engaging in topping off? Does the possibility of obtaining a 72-hour intrastate permit for $10 alleviate the alleged problem? See §478.2(3); see also Brief for Respondents 2, n. 3 (4,928 temporary permits were issued in 2004). If the fees ($100 and $10) discourage topping off, does that local commercial effect make a significant interstate difference? Would a variable fee (of the kind the truckers advocate) eliminate such difference? The minimal facts in the record tell us little about these matters. Compare App. 6061, Supplemental Affidavit of Thomas R. Lonergan ¶10(e) (official of the Michigan Public Service Commission stating that topping off is rare for most interstate carriers because it disrupts schedules and shipping patterns), with Reply Brief for Intervening Plaintiffs-Appellants in Nos. 226122, 226137 (Ct. App. Mich.), Exh. A, Supplemental Affidavit of James C. Crozier ¶6 (TNT Holland frequently tops off interstate loads). And at oral argument, ATA conceded the absence of record facts that empirically could show that the $100 fee significantly deters interstate trade. Tr. of Oral Arg. 5.
Neither does the record show that the flat assessment unfairly discriminates against interstate truckers. The fee seeks to defray costs such as those of regulating vehicular size and weight, of administering insurance requirements, and of applying safety standards. App. to Pet. for Cert. 44a. The bulk of such costs would seem more likely to vary per truck or per carrier than to vary per-mile traveled. See 255 Mich. App., at 612617, 662 N. W. 2d, at 799801. And that fact means that a per-truck, rather than a per-mile, assessment is likely fair. Cf. Jefferson Lines , 514 U. S., at 199 (rejecting taxpayers discrimination claim in part because miles traveled within the State simply are not a relevant proxy for the benefit conferred upon the parties to a sales transaction). Nothing in the record suggests the contrary.
Nor would an effort to switch the manner of fee assessmentfrom lump sum to, for example, miles traveledbe burden free. The record contains an affidavit, sworn by a Michigan Public Service Commission official, that states that to obtain the same revenue (about $3.5 million) through a per-mile fee would require the State to create a data accumulation system capable of separating out intrastate hauls and determining their length, and to develop related liability, billing, and auditing mechanisms. App. 64, Second Supplemental Affidavit of Thomas R. Lonergan ¶2. This affidavit, on its face, suggests that the game is unlikely to be worth the candle. While petitioners argue the contrary, they do not provide the details of their preferred alternative administrative system nor point to record evidence showing its practicality. See Jefferson Lines , supra, at 195 (State is not required to use a particular apportionment formula just because it may be possible to do so).
Petitioners insist that they do not need empirically to demonstrate the existence of a burdensome or discriminatory impact upon interstate trucking, or (presumably) the unfairness of the assessment in relation to defrayed costs, or (presumably) the administrative practicality of the alternatives. They say that our earlier case, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266 (1987) , requires invalidation of the $100 flat fee, even in the absence of such proof. We disagree.
In Scheiner , this Court invalidated a flat $25 marker fee and a flat axle tax that Pennsylvania levied upon all trucks (interstate and intrastate) that used its roads, including trucks that merely crossed Pennsylvanias borders to transport, say, Ohio goods to New Jersey customers. See id., at 273275. Data showed that the fees imposed a cost per mile on interstate trucks that was approximately five times as heavy as the cost per mile borne by local trucks. Id. , at 286. The assessments largely helped to raise revenue to improve and maintain [the States] highways and bridges, id. , at 270, thereby helping to cover costs likely to vary significantly with truck-miles traveled, see ibid. And the assessments did not even purport to approximate fairly the cost or value of the use of Pennsylvanias roads. Id., at 290. In light of these considerations, Pennsylvanias lump-sum taxes threaten[ed] the free movement of commerce by placing a financial barrier around the State of Pennsylvania. Id. , at 284. We concluded that [i]f each State imposed flat taxes for the privilege of making commercial entrances into its territory, there [was] no conceivable doubt that commerce among the States would be deterred. Ibid.
The present fee, as we have said, taxes purely local activity; it does not tax an interstate trucks entry into the State nor does it tax transactions spanning multiple States. See 255 Mich. App., at 592594, 662 N. W. 2d, at 789. We lack convincing evidence showing that the tax deters, or for that matter discriminates against, interstate activities. See supra , at 5. Nor is the tax one that, on its face, would seem to call for an assessment measured per mile rather than per truck. See supra , at 6. Consequently, we lack any reason to infer that Michigans lump-sum levy erects, as in Scheiner, an impermissible discriminatory road block.
Petitioners add that Michigans fee fails the internal consistency testa test that we have typically used where taxation of interstate transactions are at issue. Generally speaking, that test asks, What would happen if all States did the same? See, e.g., Goldberg v. Sweet, 488 U. S. 252, 261 (1989) ; Jefferson Lines , supra, at 185 (test looks to the structure of the tax to see whether its identical application by every State would place interstate commerce at a disadvantage as compared with commerce intrastate). We must concede that here, as petitioners argue, if all States did the same, an interstate truck would have to pay fees totaling several hundred dollars, or even several thousand dollars, were it to top off its business by carrying local loads in many (or even all) other States. But it would have to do so only because it engages in local business in all those States. An interstate firm with local outlets normally expects to pay local fees that are uniformly assessed upon all those who engage in local business, interstate and domestic firms alike. See, e.g., Commonwealth Edison , 453 U. S., at 623624 (dormant Commerce Clause does not seek to relieve those engaged in interstate commerce from their just share of state tax burden even though it increases the cost of doing business (internal quotation marks omitted)); cf. Jefferson Lines , supra , at 187188 (in context of sales tax, the Commerce Clause does not forbid the actual assessment of a succession of taxes by different States on distinct events as the same tangible object flows along). A motor carrier is not special in this respect.
In sum, petitioners have failed to show that Michigans fee, which does not seek to tax a share of interstate transactions, which focuses upon local activity, and which is assessed evenhandedly, either burdens or discriminates against interstate commerce, or violates the Commerce Clause in any other relevant way. See Complete Auto Transit, Inc. v. Brady , 430 U. S. 274, 279 (1977) (noting that a tax will be sustained where it is applied to an activity with a substantial nexus to the taxing State; where, if applied to interstate activity, it is fairly apportioned; where it does not discriminate; and where it is fairly related to the services provided).
For these reasons, the judgment of the Michigan Court of Appeals is affirmed.
It is so ordered.
Opinion
AMERICAN TRUCKING ASSOCIATIONS, INC.
<fs fs="11">and
USF HOLLAND, INC., PETITIONERS
v.
MICHIGAN
PUBLIC SERVICE COMMISSION et al.
Justice Breyer delivered the opinion of the Court.
In this case, we consider whether a flat $100 fee that Michigan charges trucks engaging in intrastate commercial hauling violates the dormant Commerce Clause. We hold that it does not.
I
A subsection of Michigans Motor Carrier Act imposes upon each motor carrier for the administration of this act, an annual fee of $100.00 for each self-propelled motor vehicle operated by or on behalf of the motor carrier. Mich. Comp. Laws Ann. §478.2(1) (West 2002). The provision assesses the fee upon, and only upon, vehicles that engage in intrastate commercial operationsthat is, on trucks that undertake point-to-point hauls between Michigan cities. See Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , 255 Mich. App. 589, 592594, 662 N. W. 2d 784, 789 (2003). Petitioners, USF Holland, Inc., a trucking company with trucks that engage in both interstate and intrastate hauling, and the American Trucking Associations, Inc. (ATA), asked the Michigan courts to invalidate the provision. Both petitioners told those courts that trucks that carry both interstate and intrastate loads engage in intrastate business less than trucks that confine their operations to the Great Lakes State. Hence, because Michigans fee is flat, it discriminates against interstate carriers and imposes an unconstitutional burden upon interstate trade.
The Michigan Court of Claims rejected the carriers claim for three reasons. First, the $100 fee is regulatory and intended for the Motor Carrier Acts administration, which includes regulation of vehicular size and weight, insurance requirements and safety standards. App. to Pet. for Cert. 44a. Such a fee is not amenable to a fee structure based on apportionment by usage rates. Ibid. Second, the fee reflects a legitimate expression of the [S]tates concern that the welfare of its citizens be protected, and hence an appropriate exercise of the States police power. Ibid. Third, the fee does not implicate the Commerce Clause because it falls only on intrastate, not interstate, commerce. Id. , at 45a.
The Michigan Court of Appeals affirmed. It did not agree that the intrastate nature of §478.2(1) sheltered the fee from Commerce Clause scrutiny. 255 Mich. App., at 617619 , 662 N. W. 2d, at 802. Nonetheless, the court rejected the truckers claim because the statute regulates evenhandedly, id. , at 621, 662 N. W. 2d, at 804, and because the record lacked any evidence that any trucking firms route choices [were] affected by the imposition of the fee, id. , at 621, 662 N. W. 2d, at 803804. Rather, the record indicated that any effect . . . on interstate commerce is incidental, rendering the truckers claim of discrimination a matter of pure speculation. Ibid.
The Michigan Supreme Court denied petitioners leave to appeal. Westlake Transp., Inc. v. Michigan Pub. Serv. Commn , ___ Mich. ___, 673 N. W. 2d 752 (2003). We granted their petition for certiorari and consolidated the case with Mid-Con Freight Systems, Inc. v. Michigan Pub. Serv. Commn , No. 031234, a case in which interstate truckers sought review of a separate state motor carrier fee. We now affirm the Michigan courts judgment sustaining §478.2(1).
II
Our Constitution was framed upon the theory that the peoples of the several states must sink or swim together. Baldwin v. G. A. F. Seelig, Inc., 294 U. S. 511, 523 (1935) . Thus, this Court has consistently held that the Constitutions express grant to Congress of the power to regulate Commerce . . . among the several States, Art. I, §8, cl. 3, contains a further, negative command, known as the dormant Commerce Clause, Oklahoma Tax Commn v. Jefferson Lines, Inc. , 514 U. S. 175, 179 (1995) , that create[s] an area of trade free from interference by the States, Boston Stock Exchange v. State Tax Commn, 429 U. S. 318, 328 (1977) (internal quotation marks omitted). This negative command prevents a State from jeopardizing the welfare of the Nation as a whole by plac[ing] burdens on the flow of commerce across its borders that commerce wholly within those borders would not bear. Jefferson Lines, supra , at 180.
Thus, we have found unconstitutional state regulations that unjustifiably discriminate on their face against out-of-state entities, see Philadelphia v. New Jersey, 437 U. S. 617 (1978) , or that impose burdens on interstate trade that are clearly excessive in relation to the putative local benefits, Pike v. Bruce Church, Inc., 397 U. S. 137, 142 (1970) . We have held that States may not impose taxes that facially discriminate against interstate business and offer commercial advantage to local enterprises, see, e.g., Oregon Waste Systems, Inc. v. Department of Environmental Quality of Ore., 511 U. S. 93, 99100 (1994) , that improperly apportion state assessments on transactions with out-of-state components, Central Greyhound Lines, Inc. v. Mealey, 334 U. S. 653 (1948) , or that have the inevitable effect [of] threaten[ing] the free movement of commerce by placing a financial barrier around the State, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266, 284 (1987) .
Applying these principles and precedents, we find nothing in §478.2(1) that offends the Commerce Clause. To begin with, Michigan imposes the flat $100 fee only upon intrastate transactionsthat is, upon activities taking place exclusively within the States borders. Section 478.2(1) does not facially discriminate against interstate or out-of-state activities or enterprises. The statute applies evenhandedly to all carriers that make domestic journeys. It does not reflect an effort to tax activity that takes place, in whole or in part, outside the State. Nothing in our case law suggests that such a neutral, locally focused fee or tax is inconsistent with the dormant Commerce Clause.
This legal vacuum is not surprising. States impose numerous flat fees upon local businesses and service providers, including, for example, upon insurers, auctioneers, ambulance operators, and hosts of others. See, e.g., Wyo. Stat. §3336104 (Lexis 2003); S. C. Code Ann. §38710 (West 2002). Although we have long since rejected any suggestion that a state tax … affecting interstate commerce is immune from Commerce Clause scrutiny because it attaches only to a local or intrastate activity, Commonwealth Edison Co. v. Montana , 453 U. S. 609, 615 (1981) , we have also made clear that the Constitution neither displaces States authority to shelter [their] people from menaces to their health or safety, D. H. Holmes Co. v. McNamara, 486 U. S. 24, 29 (1988) (internal quotation marks omitted), nor unduly curtail[s] States power to lay taxes for the support of state government, McGoldrick v. Berwind-White Coal Mining Co., 309 U. S. 33, 48 (1940) .
The record, moreover, shows no special circumstance suggesting that Michigans fee operates in practice as anything other than an unobjectionable exercise of the States police power. To the contrary, as the Michigan Court of Appeals pointed out, the record contains little, if any, evidence that the $100 fee imposes any significant practical burden upon interstate trade. See 255 Mich. App., at 620622 , 662 N. W. 2d, at 803804. The record does show, for example, that some interstate trucks top off some interstate hauls with intrastate pickups and deliveries. See Brief for Intervening Plaintiffs-Appellants in Nos. 226052, 226122 (Ct. App. Mich.), Exh. 3, Affidavit of James C. Crozier ¶7 (licensing and fuel manager of TNT Holland Motor Express, Inc. describing this practice). But it does not tell us the answers to such questions as: How often does topping off occur across the industry? Does the $100 charge make a difference by significantly discouraging interstate carriers from engaging in topping off? Does the possibility of obtaining a 72-hour intrastate permit for $10 alleviate the alleged problem? See §478.2(3); see also Brief for Respondents 2, n. 3 (4,928 temporary permits were issued in 2004). If the fees ($100 and $10) discourage topping off, does that local commercial effect make a significant interstate difference? Would a variable fee (of the kind the truckers advocate) eliminate such difference? The minimal facts in the record tell us little about these matters. Compare App. 6061, Supplemental Affidavit of Thomas R. Lonergan ¶10(e) (official of the Michigan Public Service Commission stating that topping off is rare for most interstate carriers because it disrupts schedules and shipping patterns), with Reply Brief for Intervening Plaintiffs-Appellants in Nos. 226122, 226137 (Ct. App. Mich.), Exh. A, Supplemental Affidavit of James C. Crozier ¶6 (TNT Holland frequently tops off interstate loads). And at oral argument, ATA conceded the absence of record facts that empirically could show that the $100 fee significantly deters interstate trade. Tr. of Oral Arg. 5.
Neither does the record show that the flat assessment unfairly discriminates against interstate truckers. The fee seeks to defray costs such as those of regulating vehicular size and weight, of administering insurance requirements, and of applying safety standards. App. to Pet. for Cert. 44a. The bulk of such costs would seem more likely to vary per truck or per carrier than to vary per-mile traveled. See 255 Mich. App., at 612617, 662 N. W. 2d, at 799801. And that fact means that a per-truck, rather than a per-mile, assessment is likely fair. Cf. Jefferson Lines , 514 U. S., at 199 (rejecting taxpayers discrimination claim in part because miles traveled within the State simply are not a relevant proxy for the benefit conferred upon the parties to a sales transaction). Nothing in the record suggests the contrary.
Nor would an effort to switch the manner of fee assessmentfrom lump sum to, for example, miles traveledbe burden free. The record contains an affidavit, sworn by a Michigan Public Service Commission official, that states that to obtain the same revenue (about $3.5 million) through a per-mile fee would require the State to create a data accumulation system capable of separating out intrastate hauls and determining their length, and to develop related liability, billing, and auditing mechanisms. App. 64, Second Supplemental Affidavit of Thomas R. Lonergan ¶2. This affidavit, on its face, suggests that the game is unlikely to be worth the candle. While petitioners argue the contrary, they do not provide the details of their preferred alternative administrative system nor point to record evidence showing its practicality. See Jefferson Lines , supra, at 195 (State is not required to use a particular apportionment formula just because it may be possible to do so).
Petitioners insist that they do not need empirically to demonstrate the existence of a burdensome or discriminatory impact upon interstate trucking, or (presumably) the unfairness of the assessment in relation to defrayed costs, or (presumably) the administrative practicality of the alternatives. They say that our earlier case, American Trucking Assns., Inc. v. Scheiner, 483 U. S. 266 (1987) , requires invalidation of the $100 flat fee, even in the absence of such proof. We disagree.
In Scheiner , this Court invalidated a flat $25 marker fee and a flat axle tax that Pennsylvania levied upon all trucks (interstate and intrastate) that used its roads, including trucks that merely crossed Pennsylvanias borders to transport, say, Ohio goods to New Jersey customers. See id., at 273275. Data showed that the fees imposed a cost per mile on interstate trucks that was approximately five times as heavy as the cost per mile borne by local trucks. Id. , at 286. The assessments largely helped to raise revenue to improve and maintain [the States] highways and bridges, id. , at 270, thereby helping to cover costs likely to vary significantly with truck-miles traveled, see ibid. And the assessments did not even purport to approximate fairly the cost or value of the use of Pennsylvanias roads. Id., at 290. In light of these considerations, Pennsylvanias lump-sum taxes threaten[ed] the free movement of commerce by placing a financial barrier around the State of Pennsylvania. Id. , at 284. We concluded that [i]f each State imposed flat taxes for the privilege of making commercial entrances into its territory, there [was] no conceivable doubt that commerce among the States would be deterred. Ibid.
The present fee, as we have said, taxes purely local activity; it does not tax an interstate trucks entry into the State nor does it tax transactions spanning multiple States. See 255 Mich. App., at 592594, 662 N. W. 2d, at 789. We lack convincing evidence showing that the tax deters, or for that matter discriminates against, interstate activities. See supra , at 5. Nor is the tax one that, on its face, would seem to call for an assessment measured per mile rather than per truck. See supra , at 6. Consequently, we lack any reason to infer that Michigans lump-sum levy erects, as in Scheiner, an impermissible discriminatory road block.
Petitioners add that Michigans fee fails the internal consistency testa test that we have typically used where taxation of interstate transactions are at issue. Generally speaking, that test asks, What would happen if all States did the same? See, e.g., Goldberg v. Sweet, 488 U. S. 252, 261 (1989) ; Jefferson Lines , supra, at 185 (test looks to the structure of the tax to see whether its identical application by every State would place interstate commerce at a disadvantage as compared with commerce intrastate). We must concede that here, as petitioners argue, if all States did the same, an interstate truck would have to pay fees totaling several hundred dollars, or even several thousand dollars, were it to top off its business by carrying local loads in many (or even all) other States. But it would have to do so only because it engages in local business in all those States. An interstate firm with local outlets normally expects to pay local fees that are uniformly assessed upon all those who engage in local business, interstate and domestic firms alike. See, e.g., Commonwealth Edison , 453 U. S., at 623624 (dormant Commerce Clause does not seek to relieve those engaged in interstate commerce from their just share of state tax burden even though it increases the cost of doing business (internal quotation marks omitted)); cf. Jefferson Lines , supra , at 187188 (in context of sales tax, the Commerce Clause does not forbid the actual assessment of a succession of taxes by different States on distinct events as the same tangible object flows along). A motor carrier is not special in this respect.
In sum, petitioners have failed to show that Michigans fee, which does not seek to tax a share of interstate transactions, which focuses upon local activity, and which is assessed evenhandedly, either burdens or discriminates against interstate commerce, or violates the Commerce Clause in any other relevant way. See Complete Auto Transit, Inc. v. Brady , 430 U. S. 274, 279 (1977) (noting that a tax will be sustained where it is applied to an activity with a substantial nexus to the taxing State; where, if applied to interstate activity, it is fairly apportioned; where it does not discriminate; and where it is fairly related to the services provided).
For these reasons, the judgment of the Michigan Court of Appeals is affirmed.
It is so ordered.


Class: $.Complicated.HeartRate
- Inherits:
-
Toybox.Lang.Object
-
Toybox.Lang.Object
-
Overview
Class to update the steps
Instance Method Summary collapse
-
initialize()
Constructor.
-
updateModel() as Model
Update the model.


Home
GET Example
POST Example
Replay Prevention
Query Auth Sample Implementation
{% block content %} {% endblock %}